How to identify high speed rear in TT

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Alex Dragone
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Joined: Tue Mar 12, 2019 8:43 pm
First Name: Alex
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* REQUIRED* Type and Year of Model Ts owned: 1910 Roadster, 1911 Torpedo, 1915 Touring, 1926 Roadster
Location: Orange, CT

How to identify high speed rear in TT

Post by Alex Dragone » Sun May 24, 2020 2:42 pm

I just acquired a 26 TT truck and it has a ruckstell and Rocky Mountain brakes. I have been told that some of these TTs came with a 5:1 gear ratio rear axle. How can I identify if this truck has it? Do I have to disassemble the rear? The previous owner was said to have driven it at 35 mph or more. Any help would be appreciated. Thanks

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Humblej
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* REQUIRED* Type and Year of Model Ts owned: 1926 Canadian built coupe, 1924 TT C-cab, survivor 1924 roadster
Location: Charlevoix, Mi
MTFCA Number: 28034
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Re: How to identify high speed rear in TT

Post by Humblej » Sun May 24, 2020 3:10 pm

Jack up one wheel, crank the engine over by hand and count the revolutions of the engine and the wheel.


HPetrino
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* REQUIRED* Type and Year of Model Ts owned: 1918 TT
Location: Modesto, CA

Re: How to identify high speed rear in TT

Post by HPetrino » Sun May 24, 2020 3:26 pm

If memory serves I think if you jack up one wheel, turn the crank and count the engine revolutions it takes for one wheel revolution you need to divide by 2. 5 engine revolutions should get 2 wheel revolutions meaning it has 5:1 gears. If it takes a little over 7 engine revolutions to get 2 wheel revolutions' then it's a low speed set.

At lest that's how I remember it. If I'm wrong, somebody please correct me.

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